$D01B/53275/VIC+27: Sprite to Background Display Priority
+----------+---------------------------------------------------+
| Bit x | Sprite x: 0 = Sprite has higher Priority |
+----------+---------------------------------------------------+
Higher Priority means sprite is in front of everything.
Lower Priority means sprite is behind bit-combinations starting with
1 (e.g. %1 in hires mode and %1x in multi-color mode) and in front of
bit combinations starting with 0 (e.g. %0 in hires mode and %0x in
multi-color mode). So we get the following priority-tables:
Hires: Bit=0 < Sprite < Bit=1 ; Multi-Color: Bit=00 < Sprite < Bit = 10
Bit=01 < < Bit = 11